The hydrocracking catalyst is a bifunctional catalyst having both catalytic cracking activity and hydrogenation activity, i.e. containing both an acidic component and an active component of hydrogenation. The cracking component is generally selected from an acidic silica-alumina including: silica-alumina, zeolite molecular sieve or the mixtures thereof, and the active component of hydrogenation is generally selected from metals of VIB group and VIII group in the Periodic Table of Elements, or oxides and/or sulfides of the metals. The acidic component and the active component of hydrogenation of the catalyst are needed to be adaptively adjusted to fulfill various requirements of hydrocracking products.
CN1054150C discloses a hydro-conversion catalyst of diesel oil. The catalyst comprises a support composed of alumina, an amorphous silica-alumina and a molecular sieve, and hydrogenation-active metals supported thereon. In the catalyst, the content of WO3 is 10˜30 wt %, the content of NiO is 2˜15 wt %, the content of a molecular sieve is 5˜45 wt %, the content of alumina is 30˜70 wt % and the content of an amorphous silica-alumina is 5˜25 wt %. Said molecular sieve is a Y-type molecular sieve having a total of infrared acidity of 0.5˜1 mmole/g and a unit cell size of 2.436˜2.444 nm. Said alumina is a micropore alumina with a pore volume of 0.8˜1.1 ml/g and a surface area of 230˜400 m2/g.
CN1184843A discloses a hydro-conversion catalyst of diesel oil. The catalyst has a composition of 40˜80 wt % of an alumina, 0˜20 wt % of an amorphous silica-alumina and 5˜30 wt % of a molecular sieve which is a Y-type of molecular sieve with a pore volume of 0.40˜0.52 ml/g, a specific surface area of 750˜900 m2/g, a unit cell sizes of 2.420˜2.500 and a silica-alumina ratio of 7˜15, and 10˜30 wt % of VIB Group metal and 2˜15 wt % of VIII Group metal oxide.
U.S. Pat. No. 5,030,780 discloses a saturation process of aromatic compounds which uses a catalyst containing hydrogenation metals supported on a support. Said catalyst support contains a zeolite and a porous heat-resistant inorganic oxide, especially a silica-aluminum heat-resistant inorganic oxide dispersed in an alumina matrix. Said zeolite includes various crystalo-silica-alumina zeolites known in nature or synthesized artificially, such as faujasite, mordenite, erionite zeolite, Y-zeolite, X-zeolite, L-zeolite, Ω-zeolite, ZSM-4 zeolite, Beta-zeolite and the like.
CN1055961C discloses a hydrocracking catalyst particularly suitable for producing middle fraction oil, containing an amorphous silica-alumina component and a micropore alumina adhesive, in which the content of amorphous silica-alumina is 30˜60 wt %, and at least one of Group VIB elements and at least one of Group VIII elements, the total content of the metal oxides for hydrogenation is 20-35 wt %, and the balance is micropore alumina adhesive, characterized in that the catalyst has a specific surface area of 150˜300 m2/g, a pore volume of 0.25˜0.50 ml/g, a distribution of 4˜15 nm pores in the range of 60˜90% and an infrared acidity of 0.30˜0.50 mmol/g.
CN1400284A discloses a hydrotreating catalyst of diesel oil, comprising a support and molybdenum and/or tungsten and nickel and/or cobalt supported thereon, characterized in that said support is composed of alumina and zeolite with a weight-ratio of alumina to the zeolite in the range of 90:10˜50:50; said alumina is a mixed alumina of a micropore alumina and a macropore alumina with a weight-ratio of 75:25˜50:50, wherein the micropore alumina is an alumina of which the pore volume having a pore diameter of less than 80 Angstrom accounts for more than 95% of the total pore volume and the macropore alumina is an alumina of which the pore volume having a pore diameter of 60˜600 Angstrom accounts for more than 70% of the total pore volume.
Hydrocracking catalysts provided by the prior art can meet the requirement of some hydrocracking reactions, but aromatic-saturation and ring opening activity thereof are still low.